HTML & CSS – W3C

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HTML (the Hypertext
Markup Language) and CSS (Cascading Style Sheets) are two
of the core technologies for building Web
pages. HTML provides the structure of the page, CSS the
(visual and aural) layout, for a
variety of devices. Along with graphics and scripting, HTML and CSS
are the basis of building Web pages and
Web
Applications . Learn more below
about:

What is HTML?

HTML is the language
for describing the structure of Web
pages. HTML gives authors the means to:

  • Publish online documents with headings,
    text, tables, lists, photos, etc.
  • Retrieve online information via
    hypertext links, at the click of a
    button.
  • Design forms for conducting transactions
    with remote services, for use in
    searching for information, making
    reservations, ordering products, etc.
  • Include spread-sheets, video clips,
    sound clips, and other applications
    directly in their documents.

With HTML, authors describe the structure
of pages using markup. The
elements of the language label
pieces of content such as “paragraph,”
“list,” “table,” and so on.

What is XHTML?

XHTML is a variant of HTML that uses the
syntax of XML,
the Extensible Markup Language. XHTML has
all the same elements (for paragraphs,
etc.) as the HTML variant, but the syntax
is slightly different. Because XHTML is an
XML application, you can use other XML
tools with it (such as XSLT, a
language for transforming XML content).

What is CSS?

CSS is the
language for describing the presentation of
Web pages, including colors, layout, and
fonts. It allows one to adapt the presentation
to different types of devices, such as
large screens, small screens, or
printers. CSS is independent of HTML and
can be used with any XML-based markup
language. The separation of HTML from CSS
makes it easier to maintain sites, share
style sheets across pages, and tailor pages
to different environments. This is referred
to as the separation of structure (or:
content) from presentation.

What is WebFonts?

WebFonts is a technology that enables people to use fonts on demand over the Web without requiring installation in the operating system. W3C has experience in downloadable fonts through HTML, CSS2, and SVG. Until recently, downloadable fonts have not been common on the Web due to the lack of an
interoperable font format. The WebFonts effort plans to address that through the creation of an industry-supported, open font format for the Web (called “WOFF”).

Examples

The following very simple example of a
portion of an HTML document illustrates how
to create a link within a paragraph. When
rendered on the screen (or by a speech
synthesizer), the link text will be “final
report”; when somebody activates the link,
the browser will retrieve the resource
identified by
“http://www.example.com/report”: 

<p class="moreinfo">For more information see the
<a href="http://www.example.com/report">final report</a>.</p>

The class attribute on the
paragraph’s start tag (“<p>”) can be
used, among other thing, to add style. For
instance, to italicize the text of all
paragraphs with a class of “moreinfo,” one
could write, in CSS: 

p.moreinfo { font-style: italic }

By placing that rule in a separate file,
the style may be shared by any number of
HTML documents.

More Information

For more information about HTML and CSS,
see tutorials for HTML and CSS.

For advanced document transformations and
layout beyond CSS, see XSLT
& XSL-FO.

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